Improvement in reversible center pinion tor watches



dished states agate-1d Gtjijiinr I ALMON TWING, Ol WALTHAM, MASSACHUSETTS.

Letters Patent No. 106,432, dated August 16, 1870.

The Schedule referred to in these Letters Patent and making part 9f the same.

To all whom it may concern:

Be it known that I, ALMON TWING, of \Yaltham, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in \Vatch Mechanism for preventing the train of gear-wheels and parts li'ominjnry by the breaking of the mainspring, &c.; and the following 'is a full, clear, and exact description of the same, reference being had to the accompanying drawing making a part of this specification, in \\'hich Figure 1 represents a top view or plan of a watchplate, showing the barrel or mainspring cylinder, with spiral cog-wheel, pinion, and center time-wheel.

Figure 2 shows a side or edge view of the same, with the center shaft and collar, on which the spiral center pinion is placed to operate, or a section through at xx.

Figure 3 shows an isometrical enlarged view of the center wheel, with the collar, ccntenshaft, pin or hub, and the spiral-leavcd pinionr Figure 4 is a greatly-magnified view of the central portion of the centcrpinion and the face of the collar on the shaft, showing the hub or pin projecting from the collar, and the notch or recess in the hub or central portion of the pinion.

The object of my invention is to prevent injury to the train of the watch by the breaking of the mainspring, or imperfect action of the click and ratchet.

My invention consists in the oblique-cut gear on the barrel for holding the mainspring, and the corresponding oblique-cut pinion on the arbor or center shaft, to work loosely, the pinion being provided with a notch or recess in the under side of its hub, to form a clutch when in contact with a pin or projection, on the shoulder-plate of the arbor, to which the center wheel is attached, so that, when the power of the mainspring is exerted on the movement, the peculiar form of the inclined teeth and the oblique leaves of the pinion will keep the pinion down, resting firmly on the shoulder of the arbor, locked to the pin in the plate, and drive the wheel-trains of the mechanism of the watch. But, when the sudden reverse or backward motion is given, as from the breaking of the mainspring, or the slip of the click or the ratchet, the pinion will instantly be raised otf the pin or projection, and relieve the whole, so that no dan'iage by the bending or breaking of the cogs or pivots can takeplace.

To enable others to make my improvement in watch mechanism, Lwill describe it more in detail.

Referring to the drawing The plates Aand A are constructed in the usual manner. The mainspring barrel B is provided with in-- clined teeth or cogs, b b b, and also the center pinion G has spiral leaves, 0 c c, to correspond with the cogs b I) b on the barrel-wheel.-

In the under side of the hub of the pinion O there is a notch or recess, d. One side is made at a right angle, and the other is beveled off, for the purpose of forming a clutch when in contact with a pin or projcction, e, on the shoulderfof the center shaft or arbor D, so as to drive the center wheel E in the proper direction, so as to move the whole train of mechanism when the power of the mainspring is applied.

The inclined side of the notch (Z will allow the pinion 0 to slide on the arbor or center shaft D when the motion of the barrel .B is reversed, and liberate the clutch and relieve the train of gear-wheel and the escapement from any jar or damage by the breaking oi the mainspring, or the imperfect action of the pawl and ratchet.

The oblique gear or inclined cogs b b b, and the position of their hearing on the reverse inclined leaves 0 c c of the pinion G, will securely hold the pinion on the clutch-pin c as long as the power of the mainspring is bearing upon it. But as soon as the pressure is relieved, and the motion of the barrel is reversed, the angle of the cogs will throw the pinion on" the clutch, it sliding sntficiently on the arbor D for that purpose, without throwing the cogs c c 0 out of gear with the cogs I) b b in the barrelwheel B, but at the same time be instantly and entirely freed from the train of mechanism.

It is a well-known fact that watches are often much injured, and sometimes nearly or quite ruined, by the breaking of a mainspring or the imperfect action of the click and" ratchet, a defect which is perfectly remedied by my invention, as above described.

What I claim as new in watch mechanism, and dcsire to secure by Letters Patent, is-

The loose reversible center pinion G, with recess (1, for engaging with the clutch-pin con the center wheel, and provided with oblique leaves or teeth 0 c, engaging with similarly-cut teeth on the barrel-wheel, t'or the purpose of automatically releasing the said pinion on the recoil from the rupture of the mainspring, as shown and described.

In testimony whereof I hereunto subscribe my name in the presence of- .ALMON TWING.

Witnesses:

DANL. F. VILEs, H. SMITH. 

